The present invention relates to a fastener feeding and driving apparatus which is designed to serially drive fasteners into a workpiece. Apparatus of this type typically comprise a vibrating feed hopper, and a feed or escapement assembly for receiving the fasteners from the deliver chute of the hopper and for serially delivering the fasteners through a discharge tube to a hand held power driven tool. Apparatus of this general type are further described, for example, in the U.S. patents to Willis, U.S. Pat. No. 4,278,184; McDonald, U.S. Pat. No. 3,247,847; and Viner, U.S. Pat. No. 4,114,663.
While the known apparatus are generally suitable for their intended use, the control systems for actuating the various components of the apparatus are often complex and unreliable. Also, the feed or escapement assemblies for feeding the fasteners to the power driven tool are susceptible to jamming. As a specific example, a fastener feed assembly of known design incorporates a slide which is moved by a spring laterally to a fastener pickup position when the trigger on the driver is released. When the trigger is closed, the slide is moved by air pressure laterally to a discharge position such that the fastener drops into the delivery line leading to the driver. Also, air is blown into the opening of the delivery line as the slide moves laterally, and upon the fastener reaching the delivery line, the fastener is thereby blown into the delivery line. In this prior apparatus, the air delivered into the delivery line becomes pressurized, and it may become turbulent before the fastener drops into the delivery line, and these conditions can result in the fastener becoming hung up and unable to drop into the delivery line. This in turn can result in the jamming of the mechanism, particularly if the trigger is again closed by the user of the apparatus.
It is accordingly an object of the present invention to provide a fastener feeding and driving apparatus of the described type which effectively overcomes the above noted limitations and disadvantages of the known equipment.
It is a more particular object of the present invention to provide a fastener feeding and driving apparatus having a simplified and reliable control system for actuating the various components of the apparatus.
It is still another object of the present invention to provide a fastener feeding and driving apparatus having a fastener feeding assembly which is capable of highly reliable operation, and which is of relatively simple construction so as to minimize its cost.